"""
字符串相关操作模块
"""

# 反转字符串
def str_reverse(s):
    return s[::-1]

# 按照下标a，b，对字符串s进行切片
def substr(s, a, b):
    return s[a:b + 1]

if __name__ == '__main__':
    print(str_reverse("abcde"))
    print(substr("abcde", 1, 3))